Mars

Mars

Mars, the Red Planet, is fourth from the sun, orbiting at about 1.5AU, or 228,000,000km. Mars has long been the subject of speculation as to whether it harbours life. Before our modern age of space exploration, some astronomers used to fancy irrigation canals on its surface, a sure sign of intelligent life. Since then, modern space probes and telescopy have destroyed the belief in canals and intelligent Martians; but the question of whether primitive Martian microbes may exist is still open. Mars has a thin, cool atmosphere about 100 times thinner than that of the Earth, made mostly of carbon dioxide, and with a mean surface temperature of -63℃. The polar caps are made mostly of frozen carbon dioxide and water. Human beings have managed to land several robotic probes on the surface of Mars, including the famous Sojourner radio-controlled land rover. [TB] {EA}